Exoplanet search with astrometry

TL;DR

This paper discusses how upcoming interferometric astrometry instruments like PRIMA can improve exoplanet detection by measuring star positions with high precision, enabling determination of planetary orbits and masses.

Contribution

It introduces the narrow-angle astrometry technique with PRIMA, detailing its implementation, potential to find new exoplanets, and necessary preparatory observations.

Findings

PRIMA will enable precise astrometric detection of exoplanets.

Astrometry can determine orbital inclination and true planetary mass.

Preparatory observations are essential for successful detection.

Abstract

Searching for extrasolar planets by direct detection is extremely challenging for current instrumentation. Indirect methods, that measure the effect of a planet on its host star, are much more promising and have indeed led to the discovery of nearly all extrasolar systems known today. While the most successful method thus far is the radial velocity technique, new interferometric instruments like PRIMA at the VLTI will enable us to carry out astrometric measurements accurate enough to detect extrasolar planets and to determine all orbital parameters, including their orbit inclination and true mass. In this article I describe the narrow-angle astrometry technique, how it will be realized with PRIMA, what kind of planets we can find, and what kind of preparatory observations are required.